Conservative management of acoustic neuroma: a meta-analysis and proposed treatment algorithm.

OBJECTIVES/HYPOTHESES: Conservative management is a viable treatment alternative for acoustic neuroma. Using previous studies to provide evidence-based support, we have attempted to more clearly define the role of conservative management.

STUDY DESIGN

Retrospective review of literature and patient charts.

METHODS

Published studies on conservative management of acoustic neuroma were found using a key word search through PubMed in addition to the bibliographies of these selected studies. A spreadsheet was made to tabulate the selection criteria for conservative management, duration and frequency of follow-up, patient demographics, initial tumor size and rate of growth, change in hearing status, and the need for definitive treatment.

RESULTS

A total of 21 studies comprising 1,345 patients were included in our meta-analysis. The average length of follow-up these studies was 3.2 years. The average initial tumor size was 11.8 mm (n = 900); 43% of 1,244 acoustic neuromas showed growth, whereas 57% showed either no growth or tumor regression. The average growth rate was 1.9 mm/year in 793 individuals. Hearing loss occurred in 51% of 347 individuals. In 15 studies, 20.0% of 1,001 individuals eventually failed conservative management.

CONCLUSIONS

Our meta-analysis supports the role of conservative management of acoustic neuromas in properly selected patients on the basis of a slow overall rate of growth and a substantial incidence of no growth. However, the lack of predictive factors, the relatively short duration of follow-up, and the variability of inclusion criteria underscore the need for continued collection of long-term data. An algorithm for acoustic neuroma management is proposed based on initial tumor size, patient age, and hearing status.